The manual for my Toyota said change the coolant after 7 years, then every 5 years after that.
What did I do? I changed it after 5 years (24,000 miles). The old coolant looked perfect.
I don’t care that I did it early. The coolant was a lot cheaper than the parts it protects.
Plus, I could simply drain and refill with the same Toyota coolant, a simple DIY job, no need to flush.
At 10 years I’ll change the thermostat, radiator cap and hoses.
My previous cars got coolant changes every 2 years, the green stuff.
Being able to go 5 years is a luxury in comparison.

The cost of following the maintenance schedule is peanuts when compared to the cost of a new engine. I’m not sure what you think coolant is for. But one of the sure ways to kill an engine fast is to ignore the coolant. If the downside was only a new radiator then you’d be lucky. Imagine that the radiator clogs, the car overheats, the head warps and now you need a new head gasket and cylinder head work. Or imagine that before the radiator killing corrosion clogs the radiator, it rots out your heater core and your whole dash has to come out to fix that. Or perhaps it rots through a freeze plug, spilling out all of the coolant - overheating the engine, warping the head…Or it eats away the fins on your water pump, overheating the engine…etc.

Personally - I don’t care if a manual says you can go 120K or 10 years. Either one of those is way too long.

There probably is a radiator drain but, it might be impossible to get to or just not worth the trouble. A lot of people just pull the lower radiator hose. This is messy, but fast and thorough. Wear eye protection. You should plan to have 3 gallons of new coolant around and you should plan to replace the radiator cap. The stuff floating in your coolant reservoir is most likely evidence of the beginnings of corrosion that is the reason you need to keep the whole system up to date on maintenance. You should also remove the reservoir and clean that.

Coolants are highly toxic but also attractive to living things - like pets. Don’t get anything poisoned. It also has to be disposed of properly. Make sure you have a plan for that.

If you plan to start doing your own maintenance, its probably a good idea to pick up a basic repair manual. You can usually find Haynes manuals at auto parts stores. They pretty much stink, but are mostly fine if you just need a reference for the basics.

Changing fluid is a very easy and very cheap insurance policy. And 5 years is “it” for me, no matter what the book says.

Personally, I find the easiest way to drain the system is to remove the plastic splash guards and pull the lower hose from the radiator or the engine end, whichever’s more accessible. When reinstalling it, the coolant even makes a good lubricant to slip the hose back on. I also always change the clamp for a worm-drive clamp … I personally find the OEM clamps to be a to use PITA.

Oh, and be SURE you use the right coolant for the car. There ARE different types, and they’re different for a reason. you do not want to mix them up.

My mustang has a petcock valve on the bottom corner of the radiator. It only unscrews several turns and then it drains. It doesnt remove fully (i learned that the hard way and snapped the old one! - easy replacement)

But if you cant find that, removing the lower radiator hose will be easy enough. Use some channel lock pliers, squeeze the hose clamp open and slide it back, and work/wiggle the hose off. It will gush quick so make sure you have a big empty drain pan ready, eye protection, plenty of rags and absorbent stuff helps to lay down.

Make sure the engine is completely cold (hasnt been run for atleast several hours) before you drain. Then reattach the hose, and top it back up to the cold level fill line. Allow air bubbles to burp out. Run the car and check for the next couple drives for any leaks or newly surfaced air bubbles - requiring a top off once the engine is cold.

Oh, and keep your heating system on when you’re doing all this. Most vehicles have a valve that opens when the heat is on allowing the fluid to flow readily through the heater core. If you don’t turn the system on, you just might have trouble purging (of air) and refilling the heater core.